This is a complete rewrite of the GPS driver structure, with a static
main driver and separate backend drivers. This will allow proper
support for multiple GPSes, and will allow parameters to be set on the
GPS object
the old mechanism wasted most of the input bytes, and chewed a lot of
CPU, making it impractical to do GPS detection for a GPS attached
after startup
The new code is async, and detects a GPS by looking for a fully formed
packet with the right checksum for each GPS type
Nuke AP_GPS_IMU, as nothing is using it anymore.
Simplify the handling of no GPS/no fix detection.
Fix prototypes for ::init and ::read.
Update AP_GPS_Auto and corresponding example, nearly ready for primetime.
Use uint8_t rather than byte.
Strip some _error() calls to save space. More could still go.
git-svn-id: https://arducopter.googlecode.com/svn/trunk@1246 f9c3cf11-9bcb-44bc-f272-b75c42450872
Note that this is currently disabled as changes need to be made to APM to support it.
Tested with MTK, u-blox and SiRF GPS'.
git-svn-id: https://arducopter.googlecode.com/svn/trunk@671 f9c3cf11-9bcb-44bc-f272-b75c42450872